我可以将 SIGCONT 发送到正在运行的进程吗？

Question

我知道 SIGCONT 继续之前被 SIGSTOP 停止的进程。我可以在没有 SIGSTOP 的情况下多次使用 SIGCONT 吗？即，以下顺序是否有效？

SIGSTOP to process A : The process stops
SIGCONT to process A : Process resumes
SIGCONT to process A : Process already runs - this SIGCONT has no effect 
SIGCONT to process A : Process already runs - this SIGCONT has no effect 
...
SIGSTOP to process A : The process stops
SIGCONT to process A : Process resumes

Answer 1

你可以的。 TLPI 说:

When sent to a stopped process, this signal causes the process to resume (i.e., to be rescheduled to run at some later time). When received by a process that is not currently stopped, this signal is ignored by default. A process may catch this signal, so that it carries out some action when it resumes.

APUE:

Note that the default action for SIGCONT is to continue the process, if it is stopped; otherwise, the signal is ignored.